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American Journal of Astronomy and Astrophysics
2018; 6(2): 31-38
http://www.sciencepublishinggroup.com/j/ajaa
doi: 10.11648/j.ajaa.20180602.11
ISSN: 2376-4678 (Print); ISSN: 2376-4686 (Online)
The Chant Meteor Procession of 1913 – Towards a
Descriptive Model
Martin Beech1, 2, Mark Comte2
1
Campion College at the University of Regina, Saskatchewan, Canada
2
Department of Physics, The University of Regina, Saskatchewan, Canada
Email address:
To cite this article:
Martin Beech, Mark Comte. The Chant Meteor Procession of 1913 – Towards a Descriptive Model. American Journal of Astronomy and
Astrophysics. Vol. 6, No. 2, 2018, pp. 31-38. doi: 10.11648/j.ajaa.20180602.11
Received: April 5, 2018; Accepted: April 19, 2018; Published: June 28, 2018
Abstract: From an observational standpoint the Chant Meteor Procession of 9 February, 1913 is particularly remarkable,
being especially noted for its long ground track of at least 15,000 km, and for the slow motion and near parallel to the horizon
paths adopted by the meteors. The circumstances surrounding the Procession are re-considered here in terms of the successive
entry of multiple meteoroid clusters. These clusters are in turn considered to be derived from a temporarily captured Earth
orbiting object that has undergone disaggregation. It is suggested that the general observational accounts of the Procession can
be explained through the sequential entry of multiple meteoroid clusters that moved through the Earth’s atmosphere on
grazing-incident trajectories. It is further suggested that the parent object to the Procession, prior to its breakup, may have been
no more than 3 to 4-m across.
Keywords: Natural Earth Satellites, Meteoroid Ablation, Grazing Atmospheric Flight
of varying mass that entered the atmosphere simultaneously,
1. Introduction nor was it a meteor shower. Rather, it was an extended
The Chant Meteor Procession occurred in the early sequence of meteoroid clusters that entered the Earth’s
evening hours of 9 February, 1913. The event was witnessed atmosphere, at a shallow angle of trajectory, at successively
by many hundreds, if not thousands, of eye-witnesses from different times during the course of the display. The parent
both sides of the Canada-US border and as a meteoritic body of the various meteoroid groups therefore, it is argued,
phenomenon it has long been the topic of debate and broke apart many weeks to months before the Procession
speculation. The fireball observations were first investigated actually occurred, with the various components and
in detail by Clarence Chant [1, 2] and the exceptional nature meteoroid clusters being spread out along an arc at least
of the Procession was soon realized. The first sighting of 15,000 km in length.
numerous fireballs was reported from the towns of Pense and
Mortlach in southwestern Saskatchewan, Canada and 2. The Observations
additional reports were received from as far east as the island
of Bermuda and by several ships located off the northeastern Eye-witness accounts collected by Chant, Denning and
coast of Brazil [3-7]. The existing observations indicate a Mebane [1-7] not only indicate that the Procession was
remarkably long ground track of at least 15,000 km in length apparently continuous, as expressed by reports from
for the Procession, and in turn this provides a distinct Saskatchewan to at least Bermuda, but that it had the same
challenge for the construction of a viable physical general appearance from one location to the next. Essentially
explanation. Key to unraveling the Procession, it is argued all observers describe the display as consisting of numerous
here, is to view it as a distinct chain of related events. That is, meteors travelling parallel not only to each other but also to
it was not the result of one large and successively the horizon, and while eye-witness accounts provide less than
fragmenting meteoroid, or even many individual meteoroids ideal data to work with the only apparent changes reported
from one location to the next was the total number of meteors
32 Martin Beech and Mark Comte: The Chant Meteor Procession of 1913 – Towards a Descriptive Model
seen. Figure 1 shows a composite image constructed from the like that of thunder, up to several minutes after the meteors
data and eye-witness sketches obtained by Chant [1]. The were seen. Other observers reported hearing ‘swishing’
approximate ground track is shown in red, and sketches from sounds or a ‘hiss’ like that of a fire-rocket at the same time
observers located in Ontario, Canada (at Parry Sound, that the Procession was visible. Observers onboard the
Toronto, Kitchener, and Centreton) and from Bermuda sailing ship Ponape, located off Rio Grande de Norte, Brazil,
(Hamilton) are superimposed. Also shown on the map are also reported hearing sounds [7]. Such reports are entirely
star-symbols which indicate locations from which sound consistent with other fireball events and they may be
(either sonic and/or electrophonic) were reported. It is argued attributed to sonic booms and the production of electrophonic
here that the telling feature of the various accounts is not so sounds [9-13]. The production of sonic booms is particularly
much the number of individual meteors and/or their interesting since it indicates that meteoritic material more
brightness, but the fact they moved in apparent groupings, than likely did reach the ground, although no meteorites were
and that all of the various meteors moved on a path actually recovered.
essentially horizontal to the horizon. Eye-witness accounts of
the duration times of fireballs and the arc lengths traveled on 3. A Preliminary Model
the sky are notoriously poor and difficult to work with, but
Chant [1, 2], Denning [3] and Pickering [4, 5] all determine a Given the more than 100 years that have passed since the
characteristic velocity of about 8 km/s and a near constant Procession took place, and the complete lack of any
atmospheric path height of 50 ±10 km altitude. Under these instrumental data, it is not possible to directly model the
circumstances an observer seeing the Procession moving event in detail. This being said, a model that accounts for the
from horizon to horizon, and passing through their zenith at greater bulk of the observations, such as they are, can be
the mid point, would witness a procession lasting some 3 constructed and the circumstances leading-up to the
minutes in duration. The account of J. E. Skidmore from appearance of the display may at least be assessed. The idea
Cobourg, Ontario seems particularly apropos: “they glided that the Procession was something all together different from
along so leisurely and did not seem to be falling as meteors the passage of a single, large, fragmenting meteoroid passing
usually do, but kept a straight course about 45o, or a little through the atmosphere was voiced early-on [2, 3, 4]. Indeed,
more, above the horizon. Our first impression was that a fleet both Chant [1] and Denning [3] argued that the objects
of illuminated air-ships of monstrous size were passing. The forming the Procession were captured Earth satellites. In
incandescent fragments themselves formed what to us looked 1939, C. C. Wylie [14] suggested that the event was a
like the illuminations, while the tails seemed to make the “normal meteor shower” – a suggestion that O’Keefe [15]
frame of the machine. Sometimes there would be just a single strongly argued against in 1959. Indeed, O’Keefe suggested
collection, forming a single ship; then in a half-minute that the fireballs were derived from a circum-terrestrial ring
several collections would pass, looking like ships traveling in of material formed through the ejection of material from
company. It took fully 3 minutes to pass. There was no noise; lunar volcanoes (he additionally suggested that the
only beauty, beauty!” [1]. Procession should be named the Cyrillid meteor shower,
The velocity determination of about 8 km/s for the meteors since the event took place on the feast day of Saint Cyril of
seems particularly telling with respect to the encounter Alexandria). In 1964 O’Keefe [16] additionally suggested
conditions, since it suggests that the meteoroids in the that a link might exist between the Cyrillid’s and terrestrial
procession were moving along temporary Earth-orbit tektites, the latter being derived from asteroid impacts upon
captured trajectories. The orbital velocity Vorb at height h the Moon. O’Keefe’s ideas on both tektite origins and the
above the Earth’s surface is Cyrillid shower have not proved popular, and they are
generally dismissed in terms of revised ideas in the modern
= 1− (1) era. For all this, however, the idea that the 1913 Procession is
related to the Earth undergoing an encounter with a string of
Where M and R are the mass and radius of the Earth. For h natural satellites is still robust [17]. Indeed, Granvik,
= 50 km, so Vorb = 7.9 km/s. Such temporary capture events, Vaubaillon and Jedicke [18] have argued that the Chant
taking place while the meteoroid moves through the Earth’s Meteor Procession has its origins within a sub-group of near-
atmosphere, undergoing active ablation, are not common, but Earth objects (NEOs) that can produce temporarily captured
they have been observed. The conditions that favor the orbiters (TCOs) or minimoons. Granvick and co-workers
occurrence of such events are a low angle of entry to the estimate that there is at least one 1-m sized TCO in the near-
horizon, low initial entry speed, and a small physical size [8]. Earth environment at any one time. The capture rate for 5 –
Sounds were reported from many locations along the 10 m sized TCOs is estimated to be on a decadal scale, while
Procession track (see figure 1). An observer in Warren, 100 m sized TCOs are only likely to be encountered on
northwestern Minnesota recorded that upon seeing a brilliant timescales of order 100,000 years. Furthermore, Granvick
body light-up the sky a rumble sound like that of railway and colleagues find that perhaps of order 0.1% of all
trains or distant waterfalls was heard. Observers in southern meteoroids that enter the Earth’s atmosphere are TCOs. In
Ontario and northern Pennsylvania, as well as in New York addition, Granvick et al., argue that the most likely time for
state, reported hearing rumbling sounds like cannon-fire, or TCO capture is when Earth is near perihelion (from late
American Journal of Astronomy and Astrophysics 2018; 6(2): 31-38 33 December, through January to early February) and that the been labeled as a TCO prior to Earth impact [21] – this object typical Earth-atmosphere encounter speed of TCOs will be of entered the Earth’s atmosphere at a relatively low angle of 33 order the Earth’s escape velocity ~ 11.3 km/s. degrees to the horizon, had an estimated mass of 5 kg, giving In principle every planet within the solar system has the it a diameter of some 15-cm, and an atmospheric entry speed potential for acquiring TCOs. Fedorets, Granvik and Jedicke that was just 11.2 km/s. [19], for example, argue that comet Shoemaker-Levey–9 The Chant Meteor Procession of 13 February 1913 appears (comet D/1993 F2) was a TCO of Jupiter for some 25 years to be a good candidate object for TCO status. The time of the before the various components of its fragmented nucleus event, early February, and its slow apparent speed are plunged into the planet’s upper cloud deck in July of 1994. consistent with the predictions outlined by Granvick et al. The only confirmed terrestrial TCO is that of asteroid 2006 [18]. Here it is suggested, however, that the parent object RH120; a NEO with a heliocentric orbit very similar to that of broke apart before the individual fragments, or meteoroid Earth [20]. This 2-3-meter sized object undergoes a close clusters, encountered the Earth’s atmosphere along shallow- encounter with the Earth-Moon system approximately every angle trajectories. The parent object is taken therefore to have 20 years and it was in fact discovered as a TCO – a status had a loose, rubble pile, structure and it is supposed that at that it held from September 2006 to June 2007. After leaving some stage as it orbited the Earth it passed close to or even Earth orbit in 2017, 2006 RH120 entered into an Amor-class within the Earth’s Roche radius – that is within 200,000 km NEO orbit. Its next close encounter with the Earth will be in of the Earth – and gently separated-out into a string of 2028. A short, one-month duration TCO designation has fragments and meteoroid clusters. It was the entry of these additionally been applied to the NEO 1991 VG, and this 5 to fragments, in a staggered and sequential fashion, that resulted 10-meter sized object is the potential target of NASA’s Near in the appearance of the Chant Procession. The details of this Earth Asteroid Scout mission (a CubeSat and solar sail scenario are investigated below. Firstly, the atmospheric spacecraft system) presently scheduled for launch in late flight and meteoroid ablation conditions are considered. 2019. The bright European Network fireball EN130114, Second, a series of possible model outcomes are described, observed over Europe on 13 January, 2014 has additional and thirdly a discussion for future work is presented. Figure 1. Schematic of the ground track for the Chant Meteor Procession (red line). The locations from which various eye-witness reports were collected [1 – 7] are shown by small black dots. Locations from which either sonic booms or electrophonic sounds were reported are indicated by yellow stars. The inset drawings of the Procession are taken from various eye-witness accounts [from ref. 1], and they illustrate the common description that the meteors moved in clusters and along trajectories that ran parallel to the horizon.
34 Martin Beech and Mark Comte: The Chant Meteor Procession of 1913 – Towards a Descriptive Model
4. The Equations of Meteoroid Ablation
8 Nu 1
Within the context of a non-plane-parallel atmosphere, the Λ= (10)
γ Re Pr Γ
equations of meteoroid ablation and motion are as follows
[22]: where γ = 1.4 is the ratio of specific heats for air, Nu is the
Nusselt number, and Pr is the Prandtl number. Melosh and
dV A
= −Γ ρ atm V 2 + g sin(θ ) (2) Goldin [24] provide formula for evaluating the Nusselt
dt m number (defined as the ratio of the convective to radiative
heat transfer) in terms of the Mach number M = V/ c, where V
Λ 2
3 V − Vdark
2
dm
= − ρ AV (3) is the velocity of the meteoroid and c = γ RTat is the
atm
dt 2ζ V2 atmospheric sound speed, with R = 287 J/K/kg being the gas
constant for air, and Tat being the atmospheric temperature.
dθ 1 V cos(θ )
=
dt mV
(
mg cos(θ ) − 2 Clift ρatm AV −
1 2
)R+h
(4) The Prandtl number Pr = CP µ k = 0.72 is the ratio of the
kinetic viscosity to the thermal diffusivity. In evaluating the
Prandtl number Pr the specific heat of air is taken to be CP =
dh
= −V sin(θ ) (5) 1005 J/kg, the dynamic viscosity is taken to be µ = 1.8x10-5
dt Ns/m2, and the thermal conductivity is set as k = 0.025
W/mK. The atmospheric density variation with height is
dX V cos(θ ) determined via a least squares polynomial fit to the
= (6)
dt 1+ h R NRLMISE-00 [25] atmosphere model sequenced at 5 km
intervals over the range 0 to 400 km in altitude. The
where m is the meteoroid mass, V is the meteoroid velocity, A NRLMISE-00 model is also used to evaluate the atmospheric
is the surface area of the meteoroid presented to the sound speed, via a series of least square polynomial
oncoming airflow, g is the acceleration due to gravity at equations in height constructed so as to describe the variation
height h, R = 6371 km is the radius of the Earth, ρatm is the in atmospheric temperature Tat.
atmospheric density at altitude h, θ is the flight angle to the A meteoroid will undergo fragmentation during its
horizon, Clift is the lift coefficient (taken as being zero in this atmospheric flight if the ram pressure Pram of the on-coming
study), and ζ is the enthalpy of melting and vaporization. The airflow exceeds the compressive strength σcom of its
term Vdark in equation (3) is the dark-flight velocity limit, constituent material. Accordingly, the numerical code follows
such that for V < Vdark = 2 kms-1 vigorous mass loss via the variation in the ram pressure expressed as: Pram = Γ ρ V 2,
ablation is assumed to have stopped. Equation (6) describes where V is the velocity, Γ is the drag coefficient and ρ is the
the down-range, ground track distance X along the Earth’s atmospheric density. Once Pram > σcom fragmentation is
surface. Rather than being assumed constant, the drag assumed to occur. Characteristic values for which meteoroids
coefficient Γ and the heat transfer coefficient Λ are evaluated have been observed to fragment correspond to σcom being of
according to the characteristics of the oncoming airflow and order 1 to 10 MPa [26]. Our simulations additionally track
the atmospheric height. Using the Reynolds number Re as the and quantify the heights between which electrophonic sound
regime defining parameter, the drag coefficient is evaluated generation might proceed [13, 27]. This phenomenon is
as: possible once the Reynolds number Re > 106, that is the flow
is turbulent, and when the magnetic Reynolds number Rem =
Γ=
24 3
1 + Re , when Re < 1 (7) V τm/ D > D/ 10, where D is the meteoroid diameter and τm is
Re 16 the characteristic decay time for the diffusion of the magnetic
field [27]. This onset condition can be cast in terms of the
24 height h of the meteoroid being lower than the transition
1 + 0.15 Re 0.687 , when 1 < Re < 10
3
Γ= (8)
Re height htrans, where, htrans = - H ln (Re µ0/ V ρ0 D), where H is
the atmospheric scale height, ρ0 is the atmospheric density at
Γ = 0.4 , when Re > 103 (9) sea-level, and µ0 is the dynamic viscosity.
where Re = L V/ ν, with L being the characteristic dimension
of the meteoroid (taken to be its diameter), V is the velocity 5. Model Calculations
of the meteoroid through the atmosphere, and ν is the kinetic
viscosity of the atmospheric gas. Equation (7) is the Ossen In the following simulations it is assumed that the
approximation to the classic Stokes law formula, while (8) is meteoroid entry velocity is 12 km/s, that is, just above
taken from Clift et al. [23]. Equation (9) is the limiting value Earth’s escape velocity and consistent with the predicted
for the high Reynolds number value to the drag coefficient TCO Earth encounter speed [18]. Furthermore, a constant
for a sphere. The heat transfer coefficient is taken from the density for the meteoroid material of ρmet = 3400 kg/m3 is
formulation of Melosh and Goldin [24] with: adopted, this being characteristic of that expected for
chondritic meteorites, and the starting height for each
American Journal of Astronomy and Astrophysics 2018; 6(2): 31-38 35 simulation is taken to be 300 km in altitude. The initial ≈ 1600 to 2000 km. In these same simulations the calculated meteoroid mass and angle of entry into the atmosphere are ram pressure at no time exceeded 1 MPa suggesting that taken as model variables to be chosen. The modeling under the adopted conditions no fragmentation is likely. For approach adopted has been to determine the range of the the atmosphere escape tracks show in figure 2, the velocity of parameter space in mass and entry angle that allows for long, the meteoroids in the altitude range of interest is ~ 8.5 km/s near parallel to the horizon trajectories with a height of order (as revealed in figure 3), which is characteristic of that 50 ± 10 km altitude and a characteristic speed of 8 ± 1 km/s. deduced from the eyewitness accounts. Given a typical An object moving under such conditions would represent just ground path length of order 1600 km, the entire ground path one component in the Procession. Figure 2 shows the of the Procession, if always populated by such meteoroids, atmospheric height versus range variation for a series of would require a total set of some 10 to 15, 1000 kg calculations relating to a meteoroid having an initial mass of meteoroids. Such a minimally populated Procession would 1000 kg (diameter of 0.82 m) entering the Earth’s atmosphere require the pre-Earth encounter disruption of a body having at an angle of just over 12 degrees to the local horizon (at an initial mass of about 15,000 kg with an initial diameter of 300 km altitude). Figure 3 shows the velocity variation with about 2 meters. If the Procession is assumed to contain some range associated with the 1000 kg meteoroid. Meteoroids 100, say, 1000 kg meteoroids then the size of the parent having an initial mass of 500 kg (diameters of 0.7 m), with an object is increased to about 4 meters across. The arc length entry velocity of 12 km/s behave in a similar manner to that along which the various meteoroid clusters, from first to last, portrayed in figures 2 and 3, although, for the same range of would need to be spread over prior to encountering the initial entry angles, these meteoroids can attain ground paths Earth’s atmosphere will be of order the Procession ground in excess of 2500 km while situated in the altitude range 50 ± path length of 15,000 km. Assuming a gentle separation of 10 km. components during the break-up of the parent asteroid, with For the 1000 kg mass meteoroid simulations, irrespective the components having, say, a characteristic separation speed of whether ground impact or atmospheric escape occurred, of a few meters per second, then our putative string of the ground path length within the height range of interest is X meteoroid clusters would take several months to fully form. Figure 2. Atmospheric flight characteristics for a 1000 kg meteoroid entering Earth’s atmosphere at 12 km/s. Each curve is labelled according to the initial angle of entry at 300 km altitude. For θ = 12.33 degrees, the meteoroid returns to cislunar space with a velocity of 8.6 km/s. For θ > 12.34 degrees the meteoroid penetrates deep into the atmosphere and potentially delivers meteoritic material to the ground.
36 Martin Beech and Mark Comte: The Chant Meteor Procession of 1913 – Towards a Descriptive Model Figure 3. Velocity versus range variation for a 1000 kg meteoroid entering Earth’s atmosphere at 12 km/s. Each curve is labelled according to the initial angle of entry at 300 km altitude. The closest approach distance of a meteoroid to the Earth’s constant. The ram pressure for even our largest mass surface hca (assuming no atmospheric interaction) is simulation, with m = 5000 kg, did not exceed 1 MPa and calculated at an altitude of 100 km and evaluated as: hca = accordingly no significant fragmentation would be expected R[(1 + 100/R)cos (θ100) - 1], where R = 6371 km is the during atmospheric flight. This result is consistent with eye- Earth’s radius and θ100 is the flight angle to the horizon at 100 witness accounts [1 – 7], where, in general, it is reported that km altitude. It is observed from the simulation calculations the meteors moved as single (non-fragmenting) entities. For that for those meteoroids with initial masses in the range 500 just a small increase in the entry angle, say θ = 15 degrees, it < m (kg) < 5000, there is a small window, just a few is found that the maximum ram pressure for the 5000 kg kilometers wide, between 62 < hca (km) < 65 that separates meteoroid is of order 6.5 MPa, and accordingly out whether a meteoroid will escape back into space or fragmentation would be likely; the maximum ram pressure impact upon the ground. Meteoroids that pass through this experienced by a 1000 kg meteoroid with this slightly steeper window, however, will move along trajectories that result in entry angle is found to be of order 4 MPa, again indicating a meteors moving along near horizontal tracks at a near high probability of fragmentation. It is additionally found constant height. In agreement with Hills and Goda [8] it is that once the entry angle allows for deep atmosphere found that this ‘capture window’ shrinks rapidly in size with penetration then the onset condition for electrophonic sound increasing entry velocity, all other parameters being held generation is readily satisfied.
American Journal of Astronomy and Astrophysics 2018; 6(2): 31-38 37
To sum-up, it has been found from a series of numerical Chant Meteor Procession might be taken as a fairly typical
simulations that objects encountering the Earth’s upper size for a TCO [18, 19], with such objects being encountered
atmosphere at 12 km/s, with a flight angle of about 6 degrees by the Earth on a decadal basis. What made the Chant Meteor
to the horizon at 100 km altitude, will move along extended, Procession so spectacular and yet rare is that the parent
temporary Earth-orbit capture trajectories, within the height object must have first undergone disaggregation at a time
range 50 ± 10 km altitude, that vary in length from about well before the individual components encountered the
2500 km (at 500 kg initial mass) to about 1400 km (at 5000 Earth’s atmosphere, and that the entry angle for the
kg initial mass). Just a small increase in the entry angle will meteoroid trajectories was very close to being horizontal. It is
result in meteoritic material finding its way to the ground - this low entry angle condition that dramatically reduces the
that such circumstances were actually realized is evidenced probability of a long Chant Procession-like display coming
by the reports of sonic booms and electrophonic sounds, with about. Shoemaker [29] has shown that for an isotropic flux
such phenomenon requiring the deep penetration of a the probability dP that the angle of entry θ will fall in the
relatively large meteoroid into the lower Earth atmosphere. range Ψ to Ψ + d Ψ is independent of the gravity of the target
That no meteorites were recovered following the passage of body, and that dP (Ψ < θ < Ψ + d Ψ ) = sin (2 Ψ ) d Ψ,
the Procession is either a result of the relatively sparse human indicating that the most likely atmosphere entry angle is 45o.
population (compared to the present day) along the ground For the simulations presented here, in which the window for
track, or that only small (and hence not easily found) temporary Earth-orbit capture requires, at 100 km altitude, an
meteorites were produced - perhaps both of these possibilities entry angle between 6 < θ (deg.) < 7 to the horizon, the
held sway. In contrast to the meteorite producing situation, probability of encounter is of order ~ 0.5 % of events.
just a small decrease in the entry angle that allows for Only a very few meteor processions have been witnessed
temporary capture will result in a meteoroid skipping-out of over the past several centuries. That of August 18th, 1783 was
the atmosphere. Such fireballs present an interesting situation observed to travel down the eastern coast of England and
in that their atmosphere exiting velocity will be less than the southward into European skies [30]. That of July 20th, 1860
Earth’s escape velocity and accordingly they will re-enter the was witnessed from the Great Lakes region of the United
atmosphere at a later time. Atmosphere skipping fireballs are States all the way to the Eastern seaboard [31]. The eye-
not commonly recorded, but they have been observed – witness accounts pertaining to these additional events present
perhaps the best studied such fireball is that of 10 August, many similarities to those recorded for the Chant Procession,
1972 [28]. This latter object, with an estimated diameter of and the observations are suggestive of the possibility that
about 3-meters, entered Earth’s atmosphere at a speed of 15 extended procession-like events might be witnessed once
km/s and descended to an altitude of 58 km before returning every 70 to 100 years. To make further progress in
back into space. understanding the origin and atmospheric interaction of
procession-forming events, and to further determine their
6. Conclusions possible relationship to TCOs, a 21st century display is now
required with well-calibrated instrumental data being
The collected eye-witness accounts of the Chant Meteor obtained with respect to energy, speeds, magnitudes and
Procession, while always emphasising the slow, extended and atmospheric trajectories [see e.g., 32, 33]. A typical near-
near horizontal flight of the individual meteor clusters, rarely Earth asteroid having a diameter of some 4 to 6 meters will
emphasised the brightness, and this suggests that the deposit of order several tens of kilotons of equivalent TNT
meteoroid masses must have been relatively small, since the energy into the Earth’s atmosphere during an encounter [34],
larger the meteoroid mass so the brighter will it appear for a and the total energy associated with the Chant or any other
given velocity. Accordingly, it seems appropriate to populate procession could hardly be much less than this. Such energies
the initial chain of meteoroid groups by a series of perhaps, indicate that not only will optical, radio and radar
say, 50, 1000 kg mass meteoroids, and at least an equal observations likely be obtained for a procession-like event in
number of 500 kg meteoroids, moving in unison but spread the present day, but so too will infrasound data [35]. In
over an arc of some 15,000 km in length prior to addition to advanced ground-based instrumentation being
encountering the Earth. The mass and diameter of a parent available in the modern era, the ability of space-based
object capable of producing such a fragment chain would be detectors to track fragments as they move through the
of order 75,000 kg and 3.5 meters respectively. Obviously, a atmosphere [32] will additionally enhance the likelihood of
larger initial mass body could provide more fragments and finding meteoritic material on the ground [36]. Likewise, the
possibly larger ones, than the numbers just presented. coupling of meteoroid generated shock waves to the ground
Unfortunately, however, there is no observational data to help could potentially make for seismic, sonic boom,
us constrain the total number of fragments that contributed to electrophonic sound, VLF radio and electronic interference
the Chant Meteor Procession, and the numbers suggested data becoming available for analysis [13, 37, 38, 39]. On the
above constitute what might be considered a minimum historical basis that distinctive procession events occur at
number of objects that could in principle account for the intervals of order 100 years, it is to be hoped that the next
general display as a whole. With an initial diameter in the meteor procession will take place in the near future.
size range of several meters, the putative parent object to the
38 Martin Beech and Mark Comte: The Chant Meteor Procession of 1913 – Towards a Descriptive Model
[20] JPL Small-body database browser:
https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2006RH120.
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